Attachment for converting a standard typewriter to a self-correcting typewriter

ABSTRACT

An attachment adapted to be fastened to an external portion of a standard typewriter to convert it to a self-correcting one. The attachment includes first and second keys, the depression of either of which depresses the backspace key. There is a mechanism controlled by said two keys such that after the first key is depressed, the ribbon selector is left in a first position and after the second key is depressed, the ribbon selector is left in another position.

United States Patent 1 Wolowitz 1 ATTACHMENT FOR CONVERTING A STANDARDTYPEWRITER TO A SELF-CORRECTING TYPEWRITER [76] Inventor: William H.Wolowitz, 6905 Persimmon Tree Road, Bethesda, Md. 20034 [22] Filed: May16, 1974 [21] Appl. No.: 470,476

[52] US. Cl 197/181; 197/91 [51] Int. Cl. B4lJ 29/16 [58] Field ofSearch197/91, 151,172, 180, 197/181, 156

[56] References Cited UNITED STATES PATENTS 1,183,424 5/1916 Baldwin197/181 1,399,734 12/1921 Baldwin 197/181 X 1,415,293 5/1922 Ba1dwin....197/181 2,392,517 1/1946 Banister 197/181 X 3,149,711 9/1964 Wolowitz197/91 3,154,183 10/1964 Wolowitz 197/91 3,155,216 11/1964 Talmage197/181 3,180,474 4/1965 Kuhlman 197/181 [4 1 Dec. 23, 1975 3,204,7459/1965 Wolowitz 197/91 3,204,746 9/1965 Wolowitz 197/91 3,270,852 9/1966Fondiller 197/91 3,397,767 8/1968 Hobbs 197/181 3,595,362 7/1971Wolowitz 197/181 X 3,724,633 4/1973 Korb et al. 197/151 3,729,081 4/1973Ozimek et 197/181 X 3,788,442 1/1974 Lehnhal'dt et a1. 197/181 3,799,3163/1974 Davidge et a1 197/181 3,834,512 9/1974 Haugen 197/181 PrimaryExaminerWm. H. Grieb Attorney, Agent, or FirmHal1 & Myers 1 1 ABSTRACT 8Claims, 7 Drawing Figures U.S. Patent Dec. 23, 1975 Sheet 1 of23,927,748

E: m H- 3M] tmmmmyg? US. Patent Dec. 23, 1975 Sheet 2 of 2 3,927,748

ATTACHMENT FOR CONVERTING A STANDARD TYPEWRITER TO A SELF-CORRECTINGTYPEWRITER RELATED APPLICATION This application is related to my priorcopending application, Ser. No. 396,676, filed Sept. 13, 1973, entitled"Flexible Correction Auxiliaries For Use With Golf Ball Typewriters".

BACKGROUND OF THE INVENTION In my prior patents, such as US. Pat. No.3,204,746, issued Sept. 7, I965, entitled Typewriter With ErrorCorrecting Key," I have illustrated a typewriter that enables the typistto quickly and efficiently correct typing errors. However, such priorpatents show the error-correction feature as built into the typewriterat the factory or at least to be installed internally only after thetypewriter has been at least partly taken apart.

The present invention has for its object the provision of a simple,low-cost device that can be attached to an external part of a typewriterand which will convert a standard typewriter into an error-correctingone.

SUMMARY OF THE INVENTION The invention comprises a device adapted to beattached to an external part of a typewriter. The device has first andsecond keys and a mechanism which depresses the backspace key of thetypewriter if and when either of said first or second keys is depressed.The mechanism also leaves the ribbon selector in one position (selectingone field of a dual field ribbon) after the first key has beendepressed, and leaves the ribbon selector in another position (selectingthe other field of a dual field ribbon) after the second key has beendepressed.

Accordingly, if the aforesaid attachment has been applied to atypewriter and a dual-field ribbon having black and white fields hasbeen inserted into the typewriter, errors may be easily corrected asfollows: After striking the "wrong" key, thus printing the wrong"letter, the aforesaid first key is depressed to not only backspace thetypewriter but to select the white field of the ribbon. The aforesaidwrong key is again depressed obliterating the wrong letter. Theaforesaid second key is then depressed which again backspaces thetypewriter and also selects the black half of the dual ribbon. Normaltyping may then proceed.

BRIEF DESCRIPTION OF THE DRAWING In the drawing FIG. I is a plan view ofone form of a conventional typewriter, with my novel attachment addedthereto;

FIG. 2 is a front view of said typewriter with my novel attachment addedthereto;

FIG. 3 is a detail left side view of the attachment of FIGS. 1 and 2taken along section line 3-3 of FIG. 2;

FIG. 4 is a detail right side view of said attachment taken alongsection line 4-4 of FIG. 2;

FIG. 5 is a plan view of another conventional typewriter, with anotherform of attachment added thereto;

FIG. 6 is a cross-section along line 6-6 of FIG. 5 and shows a detailedview of the mechanism operated by one of the keys of the attachment;

FIG. 7 is the same view as FIG. 6 but before the key has been depressed.

DETAILED DESCRIPTION OF THE INVENTION In FIG. I, a conventional portabletypewriter has a frame 10 carrying the usual casing 11. The usualkeyboard has writing keys such as 12 and a backspace key 13. Inaddition, the typewriter has the usual ribbon selector arm 14 whichshifts a dual field ribbon from one color to the other.

My novel attachment comprises a plate 15 attached by bolts 16 andsleeves 16a to the underside of the typewriter frame 10. The plate 15has two vertical support portions 17 and 18. The vertical supportportion 17 is shown in more detail in FIG. 3 and has two keys 1) and 20pivoted at their rear ends at 21 to the support portion 17. A rocker arm22 is attached to rod 23 which rod 23 is supported by support portions17 and 18 which define holes 24 and 25 through which rod 23 passes.

When key 19 is depressed two things occur simultaneously. One of theseis that extension arm 26, which is integral with key 19, pressesdownwardly on the right hand end of rocker arm 22 and rotates itclockwise (FIG. 3) which in turn rotates rod 23 clockwise. This motionis transferred to the right side of the typewriter where it rotatesvertical arm 27 counterclockwise (as shown in FIG. 4) and thus rotatesthe forked arm 28 to move it toward the typist. This shifts the ribbonselector to one field of the dual field ribbon (not shown). A spring 29returns key 19 to normal position when it is released. The second thingwhich occurs when key 19 is depressed is that the arm 30, which supportskey 19, moves downwardly and engages arm 31 which is carried on L-shapedarm 32 which is pivoted to support portion 17 at 33. This arm 32 carriesa horizontal arm 34 which rides on top of backspace key 13 so that thelatter is depressed whenever key 19 is depressed.

Key 20 is shown in a depressed position in FIG. 3. However, assume thatit has been returned to normal and key 19 has then been depressed asaforesaid. If then key 20 is depressed, the arm 35, which is integralwith key 20, engages the left end of rocker arm 22, thus rotating shaft23 and shifting the forked arm 28 and the ribbon selector arm 14 to itsposition farthest from the typist. This selects the other field of thedual field ribbon. At the same time, as key 20 is depressed, it engagesarm 31 and thus rotates L-shaped arm 32 depressing the backspace key 13.

Let us assume that the typewriter has a dual field ribbon, one half ofwhich is black and the other half of which is white. Assume that theblack half is selected when selector arm 14 is moved away (forward) fromthe typist and the white half selected when the selector arm 14 is movedtoward the typist. Assume now that the ribbon selector arm 14 is in theforward position and the typist makes a mistake, typing a wrong letter.The following procedure is followed to effect a correction: Key 19 isdepressed which not only depresses the backspace key 13 but also shiftsselector arm 14 to its rearward position selecting the white half of theribbon. The typist then presses the key I2 representing the wrong letterto thus cover up the mistake. Key 20 is then depressed which in turndepresses backspace key I3, moves ribbon selector arm 14 forward, andtherefore places the typewriter in normal typing condition.

FIG. 5 illustrates another typewriter having a frame supporting a casing51, a backspace key 13, a ribbon selector arm 14, and the usual keyboardhaving writing keys l2.

The attachment has casing 52 which is clamped or otherwise attached tothe typewriter casing 51 by bolt 53. Keys 19a and 20a are supported byarms 54 and 55 respectively which are pivoted at 56a and 57arespectively.

When key 200 (FIG. 6) is depressed, it engages the lip 56 at the lowerend of arm 57 which is pivoted at its upper end to the casing 52. Thearm 57 rotates clockwise as the key 20a is depressed thus moving theapparatus to the positions shown in FIG. 6 where rod 58, which ispivoted at its forward end to arm 57 and to arm 59 at its rear end, isshown moved into its most leftward position. As rod 58 moves leftward,it rotates arm 59 (FIG. counterclockwise about its center pivot 60 andthus moves the forked arm 28a and the ribbon selector arm 14 toward thetypist. As key a is depressed, it also depresses arm 61 (which ispivoted at 62) thereby depressing the backspace key 13.

Similarly, depression of key 190 depresses arm 54, which depresses arm61 and the backspace key 13, and also rotates lip 63 which moves arm 64rearward and rotates arm 59 clockwise moving forked lever 28a and theribbon selector arm 14 forward (away from the typist).

The apparatus of FIGS. 5, 6, and 7 may be operated to correct mistakesin the same manner as in the case of FIGS. 1-4.

It is noted that my attachment may be added to an existing typewriterwithout preventing any of the following functions of the existingtypewriter:

a. In FIG. 1, the addition of the attachment does not impair any effortof the typist to press any of the writing keys 12; hence those keyscontinue to function as before.

b. Similarly, the backspace key 13 may still be depressed and it willstill function when depressed, as before. Even if the typist, in aneffort to depress backspace key 13, in fact depresses lever 34, thelatter will depress the backspace key 13 which will still work in itsnormal manner.

c. The parts 22, 23, 24, 25, 27 and 28 do not impair the operation ofribbon selector arm 14. That selector arm 14 may still be movedmanually, to engage printing fields, the same as before my attachmentwas added. For example, if the apparatus is in the position shown inFIG. 3, and the ribbon selector arm 14 is moved to its other position,all of the parts 22, 23, 24, 25, 27 and 28 rotate but are not restrainedby anything that positively stops them.

d. Similarly, if the casing 52 of FIG. 5 is added to an existingtypewriter, the backspace key 13 of the existing typewriter may still bedepressed, and indeed the typist may press arm 61 downwardly toindirectly operate the backspace key 13. Since arm 61 rides below arms54 and 55, they will not interfere with any downward movement of arm 34.

e. [t is equally true that none of the mechanism comprising myattachment will interfere with the typist moving ribbon selector arm 14to either of its two printing field positions. The parts 28, 56, 57, 58,etc., are not restrained in any way that interferes with a movement ofthe ribbon selector arm 14 that selects either of said two positions.

I claim to have invented:

means of the typewriter when either of said first or second keys isdepressed, and movable means which when said first key is depressedpositions said ribbon selector in a first position and which when saidsecond key is depressed positions said ribbon selector in a secondposition, and frame means for attaching said device to the typewriter toposition the device external to the typewriter in a position such thatsaid control means is in operative relation to said backspace means andsaid movable means is in operative relation to said ribbon selector.

2. An attachment device as defined in claim 1 for use with a typewriterin which the backspace means comprises a backspace key near one end ofthe keyboard and the ribbon selector includes an operating control armnear the opposite end of the keyboard, said frame means extending underthe typewriter and also extending upward along opposite sides of thetypewriter, said control means being adjacent said backspace key andsaid movable means being adjacent said control means, said movable meansand said control means being interconnected under the typewriter andadjacent the said frame means of said device.

3. An attachment device as defined in claim 1 for use in a typewriter ofthe type in which the backspace means includes a backspace key and theribbon selector includes a control element adjacent the backspace keycomprising said frame means for the attachment device including meansfor attaching said frame means to a portion of the typewriter adjacentsaid backspace key,

said frame means comprising an enclosure,

said first and second keys extending out of said enclosure, and

said movable means including means extending out of said enclosure toengage said control element.

4. in a typewriter,

a frame,

typing means including a keyboard carried by said frame,

backspace means including an element for operating the backspace means,

ribbon selector means including a mechanism for operating the ribbonselector means,

a casing carried by said frame and at least partially extending aroundsome of the operating parts of the typewriter,

the keyboard, said element and said mechanism extending out of saidcasing,

and a device attached to said typewriter and positioned outside of saidcasing, said device comprising:

a. first and second keys b. means which when either of said keys isdepressed operates said element to effect a backspace operation, and

c. means which operates said mechanism to insure that the ribbonselector means is in one position after the first key has been depressedand is in another position after the second key has been depressed.

5. An attachment for an existing typewriter that will give it additionalfunctions, said typewriter having backspace means including a backspacekey, a ribbon 1. An attachment device for use with a typewriter of 65having a plurality of printing fields and also having the type that hasa keyboard, a backspace means and a ribbon selector, comprising firstand second keys including control means for operating said backspaceribbon field selecting means including a manually operable device forcontrolling the ribbon printing field selecting means for selecting oneof the printing fields of the ribbon, comprising:

mounting means carrying the attachment and adapted to be attached to anexisting typewriter,

a first key carried by said mounting means,

a second key carried by said mounting means,

supplementary backspace means operated by the depression of either ofsaid first or second keys for operating the backspace means that is apart of the existing typewriter, all without preventing the typist fromoperating said backspace means that is a part of said typewriter,

and supplementary ribbon field selecting means which operates the ribbonfield selecting means that is on the existing typewriter, to insure thatsaid ribbon field selecting means that is on the existing typewriter isin one position after said first key has been depressed and is inanother position after said second key has been depressed, withoutpreventing the typist from also manually selecting the printing fieldsof the ribbon by operating said ribbon printing field selecting meansthat is on the existing typewriter.

6. An attachment for an existing typewriter as defined in claim 5 inwhich both the supplementary backspace means and the supplementaryribbon field selecting means is carried by said mounting means, so thatthe entire attachment is a single unit.

7. An attachment as defined in claim 5 in which the supplementarybackspace means comprises an arm that overlies the backspace key of theexisting typewriter when the attachment is mounted on said typewriter,said arm being movable downwardly in event the typist presses said arm,thereby permitting the typist to press it in order to operate thebackspace key of the existing typewriter.

8. An attachment for an existing typewriter as defined in claim 6 inwhich:

the supplemental backspace means comprises an arm that overlies thebackspace key of the existing typewriter when the attachment is mountedon said typewriter, said arm being movable downwardly in event thetypist depresses said arm thereby permitting the typist to depress saidarm in order to operate said backspace key, and

the supplemental ribbon field selecting means engages the ribbon fieldselecting means of the existing typewriter to control the ribbon fieldselection.

1 i I! i

1. An attachment device for use with a typewriter of the type that has akeyboard, a backspace means and a ribbon selector, comprising first andsecond keys including control means for operating said backspace meansof the typewriter when either of said first or second keys is depressed,and movable means which when said first key is depressed positions saidribbon selector in a first position and which when said second key isdepressed positions said ribbon selector in a second position, and framemeans for attaching said device to the typewriter to position the deviceexternal to the typewriter in a position such that said control means isin operative relation to said backspace means and said movable means isin operative relation to said ribbon selectoR.
 2. An attachment deviceas defined in claim 1 for use with a typewriter in which the backspacemeans comprises a backspace key near one end of the keyboard and theribbon selector includes an operating control arm near the opposite endof the keyboard, said frame means extending under the typewriter andalso extending upward along opposite sides of the typewriter, saidcontrol means being adjacent said backspace key and said movable meansbeing adjacent said control means, said movable means and said controlmeans being interconnected under the typewriter and adjacent the saidframe means of said device.
 3. An attachment device as defined in claim1 for use in a typewriter of the type in which the backspace meansincludes a backspace key and the ribbon selector includes a controlelement adjacent the backspace key comprising said frame means for theattachment device including means for attaching said frame means to aportion of the typewriter adjacent said backspace key, said frame meanscomprising an enclosure, said first and second keys extending out ofsaid enclosure, and said movable means including means extending out ofsaid enclosure to engage said control element.
 4. In a typewriter, aframe, typing means including a keyboard carried by said frame,backspace means including an element for operating the backspace means,ribbon selector means including a mechanism for operating the ribbonselector means, a casing carried by said frame and at least partiallyextending around some of the operating parts of the typewriter, thekeyboard, said element and said mechanism extending out of said casing,and a device attached to said typewriter and positioned outside of saidcasing, said device comprising: a. first and second keys b. means whichwhen either of said keys is depressed operates said element to effect abackspace operation, and c. means which operates said mechanism toinsure that the ribbon selector means is in one position after the firstkey has been depressed and is in another position after the second keyhas been depressed.
 5. An attachment for an existing typewriter thatwill give it additional functions, said typewriter having backspacemeans including a backspace key, a ribbon having a plurality of printingfields and also having ribbon field selecting means including a manuallyoperable device for controlling the ribbon printing field selectingmeans for selecting one of the printing fields of the ribbon,comprising: mounting means carrying the attachment and adapted to beattached to an existing typewriter, a first key carried by said mountingmeans, a second key carried by said mounting means, supplementarybackspace means operated by the depression of either of said first orsecond keys for operating the backspace means that is a part of theexisting typewriter, all without preventing the typist from operatingsaid backspace means that is a part of said typewriter, andsupplementary ribbon field selecting means which operates the ribbonfield selecting means that is on the existing typewriter, to insure thatsaid ribbon field selecting means that is on the existing typewriter isin one position after said first key has been depressed and is inanother position after said second key has been depressed, withoutpreventing the typist from also manually selecting the printing fieldsof the ribbon by operating said ribbon printing field selecting meansthat is on the existing typewriter.
 6. An attachment for an existingtypewriter as defined in claim 5 in which both the supplementarybackspace means and the supplementary ribbon field selecting means iscarried by said mounting means, so that the entire attachment is asingle unit.
 7. An attachment as defined in claim 5 in which thesupplementary backspace means comprises an arm that overlies thebackspace key of the existing typewriter when the attachment is mountedon said typewriter, Said arm being movable downwardly in event thetypist presses said arm, thereby permitting the typist to press it inorder to operate the backspace key of the existing typewriter.
 8. Anattachment for an existing typewriter as defined in claim 6 in which:the supplemental backspace means comprises an arm that overlies thebackspace key of the existing typewriter when the attachment is mountedon said typewriter, said arm being movable downwardly in event thetypist depresses said arm thereby permitting the typist to depress saidarm in order to operate said backspace key, and the supplemental ribbonfield selecting means engages the ribbon field selecting means of theexisting typewriter to control the ribbon field selection.